The invention relates to a dispenser for media, particularly for flowable pharmaceuticals, having a pump, which is required for the suction of at least one priming stroke, and having a discharge opening more particularly constructed as a spraying nozzle, which is covered by a protective cap prior to a useful or effective discharge of the medium.
Mechanical, manually operated piston pumps, normally constructed as single-acting thrust piston pumps, must prior to their initial actuation suck in the medium into the pump filled with air during manufacture. This is called priming. For this purpose a few, usually one to three strokes are required, during which the air upstream of the pump cylinder escapes through the discharge opening, whilst the medium flows in by means of a pump inlet valve. Although in the case of a pump manufactured with high precision the number of priming strokes can be forecast in a satisfactory manner it is unavoidable that at least during the last priming strokes medium passes out of the discharge opening and is e.g. atomized.
Certain pharmaceutical administered with such dispensers, e.g. in oral or nasal manner, are so specifically tailor-made to a specific clinical picture that it must be ensured that no-one other than the patient participates in the administration. Thus, e.g. a nurse preparing such a dispenser for use by the patient, may inhale the pharmaceutical if the final priming stroke is sprayed into space.
For particularly dosage-critical pharmaceuticals dispensers have already been developed (U.S. Pat. Ser. 6,234,366), which in each case release one or more actuation strokes only in specific time intervals in order to avoid overdoses.
The object of the invention is to provide a dispenser and a method for the discharge of media, in which the priming on of the pump takes place without harming the person performing said operation.
The invention defines a dispenser having locking means ensuring a priming actuation with the protective cap fitted.
According to the method of the invention the medium which may be delivered during at least one priming stroke is discharged into the protective cap.
The protective cap can receive the medium quantity sprayed, injected or dripped therein, e.g. in a sponge-like element. For the actuation stroke the protective cap is removed or optionally automatically ejected.
There are several possibilities for performing the invention. The locking means can lock the protective cap on the dispenser until at least one priming stroke has been performed. Said locking can take place mechanically and also unlocking can be brought about mechanically or by an electrical or electronic control. It is possible to design the aforementioned time-dependent locking circuit in such a way that e.g. at the start of the use cycle a specific number of priming strokes is only released if the protective cap is fitted. The latter can remain locked or it can e.g. be ensured by means of an electric contact between the protective cap and the dispenser casing that the protective cap is fitted during said priming strokes and otherwise no release takes place.
However, it is also possible in the case of a liquid medium to use the liquid released at the end of the priming stroke in order to correspondingly influence moisture-dependent components. Thus, the interior of the protective cap can contain a moisture sensor, which emits an electric signal for the release of the protective cap.
A particularly simple construction can have a moisture-dependent component, which blocks the protective cap in the dry state, whereas it softens when medium contact occurs and releases the said cap, e.g. a gelatin ring. This would have the advantage of receiving the medium passing out.
Other mechanical solutions for the extraction lock or barrier of the protective cap are possible, e.g. in the form of a counting device advanceable by actuating strokes. Thus, EP 472 915 B discloses a dispenser, which has a counting device for the number of actuating strokes in the form of a rotatable ring. Said ring can be used to block the protective cap e.g. for the first three strokes and then release the same.
Thus, a dispenser, particularly an atomizer is created, whose discharge nozzle is covered by a protective cap able to collect and store the medium discharged during the priming strokes and before the start of the useful strokes. The protective cap is secured on the dispenser during the priming strokes. This is brought about in that a locking is provided for the protective cap and which is only released when the priming strokes have been performed. This can take place by electrical actuation or by a material change under the influence of the medium to be discharged. According to a variant, the protective cap is not itself locked, but actuation is prevented if the cap is not fitted for the priming strokes.
These and further features can be gathered from the claims, description and drawings and the individual features, both singly or in the form of sub-combinations, can be implemented in an embodiment of the invention and in other fields and can represent advantageous, independently protectable constructions for which protection is hereby claimed. The subdivision of the application into individual sections and the subheadings in no way restrict the general validity of the statements made thereunder.